Grenade fuze



vFeb- 1 1959 J. L. BROWN ETAL 2,872,866

' GRENADE FUZE Fi edse t. '22. 1954 v 2 Sheets-Sheet 1 wvz/vraks LT- L'- Brown Ell- Udiernu LT. finhwurz-schild V. Viuamenaky 1-1-8.Weni 5 BY flatwdzw fi I M 91 9. ATTORNEYS Feb. 10, 1959 J. L.,BROWN ET AL GRENADE FUZE Filed Sept. 22, 1954 2 Sheets-Sheet 2 m 5 mnmmw mwimmwm sr m nfiww EU e 1A FEW .mw Emmi u w W Patented Feb. 10, 1959 2,872,866 GRENADE FUZE Julius L. Brown, Mount Vernon, N. Y., Silvio J. Odierno, Dover, N. J., and Jack Schwarzschild, Vladimir Viasmensky, and Harold G. Wenig, New York, N. Y., assignors to the United States of America as represented by the Secretary of the Army Application September 22, 1954, Serial No. 457,801

6 Claims. Cl. 102-64) This invention may be manufactured and used by or for the Government for governmental purposes Without the payment to us of any royalty thereon.

The invention relates to hand grenades and the principal object thereof is to provide a weapon wherein the greatest possible degree of safety against premature explosions is insured.

Another object of our invention is to provide arming means for a projectile of the above type to render the same safe against rough handling and dropping, and which cannot explode during o-r immediately after flight initiation if the firing mechanism should be damaged or imperfect. v

A further and more specific object of the invention is to provide a hand grenade wherein the firing pin and lead charge are maintained in spaced relation by a portion of the fuze body interposed therebetween in normal safe condition. l

A still more specific object of the invention is to provide a hand grenade wherein the firing mechanism will move at a predetermined rate to firing position during the arming cycle.

The invention will be more clearly understood from the following detailed description of one embodiment thereof taken in conjunction with the drawings in which:

Figure l is a vertical elevation in section showing the grenade fuze in assembled condition.

Figure 2 is a view taken on lines 2-2 of Figure l and looking in the direction of the arrows.

Figure 3 is a view taken on lines 3-3 of Figure 2 and looking in the direction of the arrows.

Figure 4 is a view takenon lines 4-4 of Figure 1 and looking in the direction of the arrows.

Figure 5 is a view taken on lines 5-5 of Figure 2 and looking in the direction of the arrows.

Figure 6 is a view taken on lines 6-6 of Figure l and looking in the direction of the arrows.

Refer-ring now to the drawings wherein like reference characters are used to designate like parts, reference character 18 indicates a grenade body of the usual serrated type and having an explosive charge 11 contained therewithin. The body has a threaded passage at the top adapted to accept the fuze body 12, substantially as shown. A handle 13 is -removably secured to the fuze body and has the end portion thereof bent in arcuate form to partially embrace fixed pin 14. Adjacent the end the handle is bent back upon itself forming a recess to receive removable split pin 15. A pull ring 19 is held by the pin in the usual manner. Compression spring 16 is nested in a chamber formed in the fuze body and surrounds boss 17 riveted into the handle. The boss has a portion thereof 18 of reduced diameter and arcuate form which serves as a detent, as will later be more fully explained.

The fuze body is closed at the top by a cap 20 sealed with an 0 ring 21'to maintain the same watertight. A pivot 25 is seated for rotation in the cap and acts as a bearing for a rotor 22 extending within the body. The rotor has a passage formed radially theretluough to re States Patent fiice ceive one end 23 of a torsion spring 24. The opposite end 26 of the torsion spring .is anchored in a socket 27 in the body 12, as best seen in Figure 4. During assembly the spring is prewound to drive the rotor 22 in a clockwise direction, as viewed in Figures 2 and 4 for a purpose to be hereinafter disclosed. Predetermined time delay rotation of the rotor is effected by an escapement mechanism which comprises an escapement wheel 28 rotatable freely about the pivot 25 and a pallet 29 oscillatable on an arbor 30. A gear train connects the rotor and escapement wheel 28 and comprises a gear wheel 31 formed integral with the rotor and in mesh with a pinion gear 32 on an arbor 33, a gear wheel 34 on the arbor 33 meshing with a pinion gear 35 secured to the escapement wheel 28 and freely rotatable therewith on the pivot 25, as best seen in Figure 3. A notch 36 formed in the pallet 29 receives the arcuate detent 18 and prevents rotation of the escapement mechanism and the rotor 22 until the pin 15 is removed then the handle 13 is released. The compression spring 16 then ejects the boss 17 and detent 18 with the handle and trees the escapement mechanisms for timed rotation of the rotor 22.

The arbors 30 and 33 are journalled for rotation at their upper ends in the cap 20 and at their lower ends in a fiat ring 57 supported on a shoulder 58 formed in the fuze body. Spacers are retained intermediate the cap 20 and the flat ring 57 by pins 60. V

A bore 37 is formed in the rotor 22 parallel with and radially displaced from the axis of rotation and slidably receives a firing pin 38. The fuze body has an axial bore 39 in a portion of its length to receive the rotor, the remaining lower portion thereof forming an abutment 40 which holds the firing pin in normal safe position. An arcuate groove 41 is cut in the upper surface of the abutment to prevent deformation of the pointed end 42 of the firing pin during rotation of the rotor from safe to firing position. The arcuate groove extends concentrically with the rotational axis of the rotor to a point approximately 180 remote from the safe position of the firing pin. The firing pin is held in the safe position against the bias of firing pin spring 43 whichv surrounds the reduced end 44 thereof. 1

The abutment 40 has an axial bore 45 and a counterbore 46. A shaft 47 is journalled for rotation in the bore 45 and has one end extending upwardly therebeyond and keyed to the rotor at 48. The opposite end of the shaft 47 extends downwardly into the counterbore 46 and is secured by a pin 49 to an interrupter Stl housed within the counterbore. A passageway 51, in which detonator 52 is housed extends longitudinally of the abutment from its upper surface to and in communication with the counterbore 46. An explosive lead charge 53 is secured in the interrupter 50, removed from the detonator 52, and in normal safe position of the fuze the abutment 40 separates the firing pin and lead charge 53 while the detonator is positioned 180 removed from a line passing through the firing pin and lead charge.

An elongated cup 54, carrying a booster charge 55 in its closed end, surrounds the lower part of the fuze body 12 and is crimped thereto at 56.

In the event of accidental firing of the detonator, expanding gases therefrom might rupture the side wall of the fuze body, therefore the expansion chamber 61 is formed in the interrupter 50 to provide space in addition to the passageway 51 to relieve such pressure.

The operation of the fuze is as follows:

The grenade is grasped in the hand of the user in a manner to restrain the handle 13 against release, thereafter the safety pin 15 is withdrawn and the grenade thrown. Compression spring 16 forces the handle from the fixed pin 14, carrying the detent 18 and causing the escapetnent mechanism to operate by the bias of preas /sees a: wound torsion s ring 24 against the rotor '22 and the gear train. The rotor turns Clockwise, as seen in Figures 2 and 4, 180 carrying with it the firing pin and the depending interrupter until the firing pin 38 and lead charge 53, register at opposite ends of the passageway 51. The firing pin is free to enter the passageway and strike the d'etonator 52 therein.

While we have disclosed a form of the invention presently preferred by us, various changes and modifica tions will occur to those skilled in the art after a study of the present disclosure, Hence the disclosure is to be taken in an illustrative rather than a limiting sense; and it is our desire and intention to reserve all modifications falling within the scope of the s'ubjoined claims.

Having now fully disclosed the invention what we claim and desire to secure by Letters Patent is:

1. A time delay fuze for a hand grenade comprising a body member, a booster charge in said body member, a rotor extending within said body, a firing pin carried by said rotor and radially displaced from the axis of rotation thereof, means to apply torque to said rotor, means to resist said torque whereby the said rotor turns at a predetermined rate, a passage extending through said body and communicating with said booster, the said rotor turnable at least until the said firing pin registers at said passage, detonator in said passage, and a spring to drive said firing pin through said passage into said detonator.

2. A time delay fuze for a hand grenade comprising a body member, a rotor extending Within said body member, a firing pin carried by said rotor and radially displaced from the axis of rotation thereof, a lead charge connected to said rotor and turnable therewith, means to apply torque to said rotor, means to resist said torque whereby the said rotor turns at a predetermined rate, detent means to prevent turning oi: said rotor in normal safe condition, a passage extending through said body, a detonator in said passage, means connected to said rotor normally obstructing said passage and removable therefrom whereby in final ready position of said rotor the said firing pin and the said lead charge respectively register at the said passage with the said detonator sandwished therebetween.

3. A time delay fuze for a hand grenade comprising a body member, a rotor extending within said body member, a firing pin carried by said rotor and radially displaced from the axis of rotation thereof, a lead charge depending from said rotor in coaxial relation with said firing pin, the said firing pin and lead charge normally separated by a portion of said body member extending therebetween, a means to apply torque to said rotor, means to resist said torque whereby the said rotor turns at a predetermined rate, a passage extending through said body, a de'tonator in said passage, means depending from said rotor normally obstructing said passage and removable therefrom whereby in final ready position of said rotor the said firing pin and the said lead charge respectively register at opposite ends of said passage to form a fire passage to said detonator.

4. A time delay fuze for a hand grenade comprising a body member, a booster in said body member, a cylindrical member extending within said body and turnable on its longitudinal axis, a firing pin carried by said mem' ber displaced from said longitudinal axis and parallel thereto, a lead charge depending from said rotor in coaxial relation with said firing pin, the said lead charge and firing pin normally maintained in spatial relation by a portion of said body member extending therebetween, a torsion spring urging said member to rotate, an escapernent resisting said urging whereby said member rotates at a predetermined rate, a passage extending through said body and communicating with said booster, a detonator in said passage, a cup depending from said rotor normally obstructing said passage and removable therefrom whereby in final ready position of said rotor the said firing pin and 'the said lead charge respectively register at opposite ends of said passage.

5. The invention according to claim 4 including a shaft depending from said cylindrical member, said lead charge and said cup secured in diametrically opposed relation to said shaft.

6. A time delay 'fuz'e for a hand grenade comprising a body member, a booster in said body member, a handle detachably secured to said body, a cylindrical member in said body and turnable on its longitudinal axis, a spring urged firing pin carried by said member displaced from said longitudinal 'axis and parallel thereto, a shaft depend ing from said member, a lead charge secured to said shaft in coaxial relation with said firing pin, the said firing pin and lead charge normally maintained in spatial relation by a portion of said body extending therebetween, a torsion spring engaging said member to apply torque thereto,' an escapement connected to said member to resist said torque whereby the said member rotates at a predetermined rate, said escapement comprising a gear train and an oscillating pallet, said handle engaging said pallet to prevent oscillation thereof, a passage extending through said body and communicating with said booster a detonator in said passage, a cup secured to said shaft in diametrically opposed relation to said lead charge and normally obstructing said passage whereby rotation of said member removes the said cup from the said passage and the said firing pin and lead charge respectively register at opposite ends thereof.

No references cited. 

